Set of optimizations applicable to a wireless networks operating in TV white space bands

ABSTRACT

An access point coupled to a node within a network is configured to combine channel maps provided by other access points to which the node is coupled, thereby reconciling any discrepancies between those channel maps. The access point may also combine channel maps associated with different regions that the node may occupy, thereby reducing the number of channel maps that must be transmitted to the node when the node travel between regions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional patentapplication titled “A Set of Optimizations Applicable to WirelessNetworks Operating in TV White Space Bands,” filed on Mar. 14, 2013 andhaving Ser. No. 61/782,863. The subject matter of this relatedapplication is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

Embodiments of the present invention relate generally to wirelessdigital communication and, more specifically, to a set of optimizationsapplicable to wireless networks operating in white space bands.

Description of the Related Art

A conventional wireless network system generally includes a collectionof different nodes configured to interoperate with one another. Nodesthat reside within a particular physical region may communicate with oneanother according to a set of channels that are available within thatregion. For example, if the nodes are configured to communicate on TVwhite space (TVWS) channels, then the nodes may exchange data with oneanother across any of the TVWS channels that are available within thatregion. A node residing within a given region may determine theavailable channels in that region by querying an access point for a“channel map” that specifies which channels are regionally available.

The approach described thus far is feasible in the simple networkconfiguration described above. However, modern networks have severalfeatures that make this approach problematic. In particular, in a modernnetwork, a node may be coupled to multiple different access points, andeach access point may provide the node with a different channel map.When a conventional node is presented with conflicting information inthis fashion, the node may cease to operate properly and may not be ableto fully participate in the network, which could result in low datarates. In addition, modern nodes are capable of travelling betweendifferent regions that have different channel availability, and so thechannel maps acquired by the node may frequently become obsolete. Agiven channel map may also become obsolete with time. Consequently, thenode may frequently lose network connectivity.

As the foregoing illustrates, what is needed in the art is an improvedtechnique for providing channel maps to devices that operate in anetwork.

SUMMARY OF THE INVENTION

One embodiment of the present invention sets forth acomputer-implemented method for generating a channel map for a nodewithin a network, including acquiring a first channel map that includesa first set of channels on which the node is configured to communicate,acquiring a second channel map that includes a second set of channels onwhich the node is configured to communicate, combining the first channelmap with the second channel map to generate a third channel map, andcausing the node to communicate on a channel included in the thirdchannel map.

Advantageously, the node is provided with a single channel map that isconsistent across all access points to which the node is coupled andrelevant within multiple regions that the node may occupy. Thus, thedisclosed techniques may reduce the number of channel maps that must betransmitted to the node, thereby decreasing overall network traffic.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 illustrates a network system, according to one embodiment of thepresent invention;

FIG. 2 illustrates a network interface configured to transmit andreceive data within a wireless mesh network, according to one embodimentof the present invention;

FIG. 3 is a block diagram illustrating the server of FIG. 1, accordingto one embodiment of the present invention;

FIGS. 4A-4C illustrate different portions of the network system of FIG.1 that are configured to combine channel maps associated with differentaccess points, according to various embodiments of the presentinvention;

FIGS. 5A-5B illustrate different portions of the network system of FIG.1 that are configured to generate a channel map based on the predictedposition of a node, according to various embodiments of the presentinvention;

FIGS. 6A-6C illustrate different portions of the network system of FIG.1 that are configured to combine different channel maps associated withvarious positions of a node, according to various embodiments of thepresent invention;

FIG. 7 is a flow diagram of method steps for combining different channelmaps, according to one embodiment of the present invention;

FIG. 8 is a flow diagram of method steps for generating a channel mapbased on the predicted position of a node, according to one embodimentof the present invention; and

FIG. 9 is a flow diagram of method steps for combining different channelmaps based on the predicted position of a node, according to oneembodiment of the present invention.

DETAILED DESCRIPTION

In the following description, numerous specific details are set forth toprovide a more thorough understanding of the present invention. However,it will be apparent to one of skill in the art that the presentinvention may be practiced without one or more of these specificdetails. In other instances, well-known features have not been describedin order to avoid obscuring the present invention.

System Overview

FIG. 1 illustrates a network system 100, according to one embodiment ofthe present invention. The network system 100 includes, withoutlimitation, a wireless mesh network 102, which may include a source node110, intermediate nodes 130 and destination node 112. The source node110 is able to communicate with certain intermediate nodes 130 viacommunication links 132. The intermediate nodes 130 communicate amongthemselves via communication links 134. The intermediate nodes 130communicate with the destination node 112 via communication links 136.The network system 100 may also include one or more access points 150, anetwork 152, a server 154, a router 156, a public database 158, and aprivate database 160.

A discovery protocol may be implemented to determine node adjacency toone or more adjacent nodes. For example, intermediate node 130-2 mayexecute the discovery protocol to determine that nodes 110, 130-1,130-3, and 130-5 are adjacent to node 130-2. Furthermore, this nodeadjacency indicates that communication links 132-2, 134-2, 134-4 and134-3 may be established between the nodes 110, 130-1, 130-3, and 130-5,respectively. One skilled in the art will understand that anytechnically feasible discovery protocol may be implemented withoutdeparting from the scope and spirit of embodiments of the presentinvention.

The discovery protocol may also be implemented to determine the channelhopping sequences of adjacent nodes, i.e. the sequence of channelsacross which nodes periodically receive payload data. As is known in theart, a “channel” may correspond to a particular range of frequencies.Once adjacency is established between the source node 110 and at leastone intermediate node 130, the source node 110 may generate payload datafor delivery to the destination node 112, assuming a path is available.The payload data may comprise an Internet protocol (IP) packet, anEthernet frame, or any other technically feasible unit of data.Similarly, any technically feasible addressing and forwarding techniquesmay be implemented to facilitate delivery of the payload data from thesource node 110 to the destination node 112. For example, the payloaddata may include a header field configured to include a destinationaddress, such as an IP address or IEEE Extended Unique Identifier (EUI)media access control (MAC) address.

Each intermediate node 130 may be configured to forward the payload databased on the destination address. Alternatively, the payload data mayinclude a header field configured to include at least one switch labelto define a predetermined path from the source node 110 to thedestination node 112. A forwarding database may be maintained by eachintermediate node 130 that indicates which communication link 132, 134,136 should be used and in what priority to transmit the payload data fordelivery to the destination node 112. The forwarding database mayrepresent multiple paths to the destination address, and each of themultiple paths may include one or more cost values. Any technicallyfeasible type of cost value may characterize a link or a path within thenetwork system 100. In one embodiment, each node within the wirelessmesh network 102 implements substantially identical functionality andeach node may act as a source node, destination node or intermediatenode.

The nodes 130 are configured to communicate with one another on manydifferent channels, although the set of channels available to the nodes130 may be limited for various reasons. For example, the nodes 130 mayreside proximate to a TV tower that transmits on a particular TVchannel, and so the nodes 130 may be restricted from communicating onthat particular channel. A given node 130 may acquire a list ofavailable channels associated with a region occupied by that node 130from a public database 158. The public database 158 includes channelavailability data for a wide variety of different regions where the node130 may reside. The node 130 may query the public database 158 directlyfor the list of available channels, although in practice, the node 130relies on the server 154 to perform such queries on behalf of the node130. The node 130 may communicate with the server 154 via one or more ofthe access points 150. In one embodiment, the public database 158 is aTVWS database that includes a list of available TV channels withinvarious regions.

The node 130 may also acquire a quality of service (QOS) value for eachchannel that is available in a region where the node 130 may reside. Theprivate database 160 includes channel QOS values for various channelsassociated with different regions. The node 130 may query the privatedatabase 160 directly for QOS values associated with a list of channels,although in practice, the node 130 relies on the server 154 to performsuch queries on behalf of the node 130. Again, the node 130 maycommunicate with the server 154 via one or more of the access points150. The server 154 may interact with the private database 160 in orderto determine the QOS values for each available channel and then select,from the list of available channels, those channels that have a QOSvalue that is sufficient for the operating requirements of the node 130.

As a practical example of the approach described above, the node 130could request a channel from the server 154 by transmitting latitude andlongitude values associated with the position of the node 130 to theserver 154 via access point 150-1. The server 154 could then query thepublic database 158 with those latitude and longitude values, and, inresponse, receive a list of available channels associated with thatposition from the public database 158. The server 154 could also querythe private database 160 in order to determine a QOS value for eachchannel in the list of available channels. The server 154 could thenselect one or more of the available channels, from the list of availablechannels, with QOS value that exceed a threshold value. The server 154could then provide the selected channels to the node 130 by way ofaccess point 150-1.

In various embodiments of the invention, each access point 150 mayinteract with the server 154 in order to acquire “channel maps” thatrepresent one or more lists of channels associated with one or moreregions. A channel map may include a list of available channelsassociated with just one region, or many lists of channels, where eachlist corresponds to a different region. A channel map may also includeQOS values for available channels, or, alternatively, lists of channelsthat meet certain criteria, such as, e.g. a minimum QOS value. A channelmap may be derived from information stored in public database 158 and/orprivate database 160. For example, the server 154 may generate a channelmap for a collection of different regions by querying the publicdatabase 158 for the available channels within each of those differentregions. An access point 150 may configure a given node 130 tocommunicate on a particular channel based on the channel map.

A node 130 may be coupled to more than one access point 150, and, thus,the node 130 may receive more than one channel map from those accesspoints 150. Those channel maps may be different from one another and maypresent conflicting information to the node 130. A technique forcombining different channel maps in order to resolve discrepanciesbetween those channel maps is described below in conjunction with FIGS.4A-4C and 7.

A node 130 may also travel between regions that are associated withdifferent channel maps. A technique for configuring a traveling node 130with a channel map that is relevant within the regions traversed by thenode 130 is described in greater detail below in conjunction with FIGS.5A-5B and 8. The two techniques mentioned above may also be combined, asdescribed in greater detail below in conjunction with FIGS. 6A-6C and 9.

In network system 100, an access point 150, such as access point 150-1or access point 150-2, is configured to communicate with at least onenode within the wireless mesh network 102, such as intermediate node130-1 or 130-4. Communication may include transmission of payload data,timing data, or any other technically relevant data between the accesspoint 150 and the at least one node within the wireless mesh network102. For example, a communications link 140-1 may be established betweenthe access point 150-1 and intermediate node 130-1 to facilitatetransmission of payload data between wireless mesh network 102 andnetwork 152. The network 152 is coupled to the server 154 viacommunications link 142. The access point 150 is coupled to the network152, which may comprise any wired, optical, wireless, or hybrid networkconfigured to transmit payload data between the access point 150 and theserver 154. Router 156 may be configured to coordinate communicationsbetween the access point 150 and the server 154 across communicationlink 142.

In one embodiment, the server 154 represents a destination for payloaddata originating within the wireless mesh network 102 and a source ofpayload data destined for one or more nodes within the wireless meshnetwork 102. In another embodiment, the server 154 executes anapplication for interacting with nodes within the wireless mesh network102. For example, nodes within the wireless mesh network 102 may performmeasurements to generate measurement data, such as power consumptiondata. The server 154 may execute an application to collect themeasurement data and report the measurement data. In yet anotherembodiment, the server 154 queries nodes within the wireless meshnetwork 102 for certain data. Each queried node replies with requesteddata, such as consumption data, system status and health data, and soforth. In an alternative embodiment, each node within the wireless meshnetwork 102 autonomously reports certain data, which is collected by theserver 154 as the data becomes available via autonomous reporting.Exemplary details of server 154 are described in greater detail below inconjunction with FIG. 3.

The techniques described herein are sufficiently flexible to be utilizedwithin any technically feasible network environment including, withoutlimitation, a wide-area network (WAN), a local-area network (LAN), apersonal area network (PAN), a TVWS network, a star network, and soforth. Moreover, multiple network types may exist within a given networksystem 100. For example, communications between two nodes 130 or betweena node 130 and the corresponding access point 150 may occur via aradio-frequency local-area network (RF LAN), while communicationsbetween access points 150 across the network 152 may occur via a WANsuch as a general packet radio service (GPRS). As mentioned above, eachnode within wireless mesh network 102 includes a network interface thatenables the node to communicate wirelessly with other nodes. Anexemplary network interface is described below in conjunction with FIG.2.

FIG. 2 illustrates a network interface 200 configured to implementmulti-channel operation, according to one embodiment of the presentinvention. Each node 110, 112, 130 within the wireless mesh network 102of FIG. 1 includes at least one instance of the network interface 200.The network interface 200 may include, without limitation, amicroprocessor unit (MPU) 210, a digital signal processor (DSP) 214,digital to analog converters (DACs) 220 and 221, analog to digitalconverters (ADCs) 222 and 223, analog mixers 224, 225, 226, and 227, aphase shifter 232, an oscillator 230, a power amplifier (PA) 242, a lownoise amplifier (LNA) 240, an antenna switch 244, and an antenna 246. Amemory 212 may be coupled to the MPU 210 for local program and datastorage. Similarly, a memory 216 may be coupled to the DSP 214 for localprogram and data storage. Memory 212 and/or memory 216 may be used tostore data structures such as, e.g., a forwarding database, and/orrouting tables that include primary and secondary path information, pathcost values, and so forth.

In one embodiment, the MPU 210 implements procedures for processing IPpackets transmitted or received as payload data by the network interface200. The procedures for processing the IP packets may include, withoutlimitation, wireless routing, encryption, authentication, protocoltranslation, and routing between and among different wireless and wirednetwork ports. In one embodiment, MPU 210 implements the techniquesperformed by the node, as described in conjunction with FIGS. 1 and 4-9,when MPU 210 executes a firmware program stored in memory within networkinterface 200.

The DSP 214 is coupled to DAC 220 and DAC 221. Each DAC 220 and 221 isconfigured to convert a stream of outbound digital values into acorresponding analog signal. The outbound digital values are computed bythe signal processing procedures for modulating one or more channels.The DSP 214 is also coupled to ADC 222 and ADC 223. Each ADC 222 and 223is configured to sample and quantize an analog signal to generate astream of inbound digital values. The inbound digital values areprocessed by the signal processing procedures to demodulate and extractpayload data from the inbound digital values. Persons having ordinaryskill in the art will recognize that network interface 200 representsjust one possible network interface that may be implemented withinwireless mesh network 102 shown in FIG. 1, and that any othertechnically feasible device for transmitting and receiving data may beincorporated within any of the nodes within wireless mesh network 102.

FIG. 3 is a block diagram illustrating the server of FIG. 1, accordingto one embodiment of the present invention. In this particularembodiment, server 154 comprises a computing device capable ofprocessing data by executing program instructions stored in memory.Server 154 may also comprise any type of machine capable of processingdata. As shown, server 154 includes, without limitation, a processingunit 302, input/output (I/O) devices 304, and memory 306. As also shown,processing unit 302, I/O devices 304, and memory 306 are coupled to oneanother.

Processing unit 302 may include one or more central processing unit(CPUs), parallel processing units (PPUs), graphics processing units(GPUs), application-specific integrated circuits (ASICs),field-programmable gate arrays (FPGAs), or any other type of processingunit capable of processing data. In addition, processing unit 302 mayinclude various combinations of processing units, such as, e.g., a CPUcoupled to a GPU.

I/O devices 304 may include input devices, such as a keyboard, a mouse,a touchpad, a microphone, a video camera, and so forth, as well asoutput devices, such as a screen, a speaker, a printer, a projector, andso forth. In addition, I/O devices 304 may include devices capable ofperforming both input and output operations, such as a touch screen, anEthernet port, a universal serial bus (USB) port, a serial port, etc.I/O devices 304, as well as processing unit 302 described above, areboth configured to read data from and write data to memory 306.

Memory 306 may include a hard disk, one or more random access memory(RAM) modules, a database, and so forth. In general, any technicallyfeasible unit capable of storing data may implement memory 306. Memory306 includes an application 308 that may be executed by processing unit302 to perform the various functions of server 154 described herein.Persons skilled in the art will recognize that the block diagram shownin FIG. 3 illustrates just one possible implementation of server 154,and that any system or combination of systems configured to perform thefunctionality of server 154 described herein falls within the scope ofthe present invention.

Optimizations for Wireless Networks Operating in TV White Space Bands

Each of FIGS. 4A-4C illustrates a portion of the network system of FIG.1 configured to combine channel maps associated with different accesspoints, according to various embodiments of the present invention. FIGS.4A-4C include some of the same components as those shown in FIG. 1,although certain components have been omitted, for the sake ofsimplicity, while other components have been added.

FIG. 4A illustrates a portion 400 of the network system 100 of FIG. 1configured to combine channel maps 402 and 404 associated with accesspoints 150-1 and 150-2, respectively, according to one embodiment of thepresent invention. As shown, access point 150-1 includes channel map 402and access point 150-2 includes channel map 404. Access point 150-2 isconfigured to transmit channel map 404 to access point 150-1, as alsoshown.

As discussed above in conjunction with FIG. 1, a channel map generallyrepresents one or more lists of channels associated with one or morephysical regions. A channel map may be derived from information storedin public database 158 and/or private database 160, and may thusrepresent one or more lists of available channels, QOS values for thosechannels, or simply one or more lists of channels with a threshold QOSvalue. In addition, a channel map may reflect certain constraintsassociated with the channels associated with a particular region. Forexample, a channel map could indicate that certain channels are onlyavailable during certain periods of time, and may not be availableduring other intervals of time. Further, the channel map could indicatethat particular channels have limited usability, due to, for example, anexcessive number of users communicating on those particular channels. Asa general matter, the channel maps disclosed herein may reflect a widevariety of characteristics and/or metrics associated with a set ofchannels.

In FIG. 4A, channel maps 402 and 404 include different lists of channelsassociated with a region occupied by the node 130. More specifically,channel maps 402 and 404 may represent different lists of availablechannels, different QOS values for the same set of available channels,or different lists of channels with a high QOS value, among otherpossibilities. Channel maps 402 and 404 may differ from one another fora wide variety of reasons. For example, access point 150-1 may haveacquired channel map 402 more recently than when access point 150-1acquired channel map 404. Thus, channel map 402 may represent a morecurrent list of channels associated with the region occupied by the node130. Alternatively, channel map 402 may include QOS values that werecomputed more recently than QOS values included within channel map 404.

Access point 150-1 is configured to acquire channel map 404 from accesspoint 150-2 and to then combine channel maps 402 and 404 to generatechannel map 406, thereby resolving any differences between channel maps402 and 404. In the context of this disclosure, two channel maps may be“combined” by performing any operation or sequence of operations withthose two channel maps in order to generate a third channel map. Uponcombining channel maps 402 and 404 to generate channel map 406, accesspoint 150-1 may then transmit channel map 406 to node 130. Node 130 maythen communicate with other nodes 130 according to the list of channelsincluded within channel map 406. Access point 150-1 may also transmitchannel map 406 to other nodes coupled to node 130, so that those nodesmay communicate according to a single, consistent channel map.

Access point 150-1 may combine channel maps 402 and 404 by implementinga wide variety of different techniques. For example, when channel maps402 and 404 represent different lists of available channels, accesspoint 150-1 could perform an AND operation with channel maps 402 and 404in order to identify available channels that appear within both ofchannel maps 402 and 404. Alternatively, access point 150-1 couldperform an OR operation with channel maps 402 and 404 in order toidentify available channels that appear in either of channel maps 402and 404. Access point 150-1 could then incorporate the channelsresulting from either of these two operations into channel map 406.

In embodiments where channel maps 402 and 404 include QOS values for thevarious channels included in those channel maps, access point 150-1 mayimplement more diverse combination techniques. For example, access point150-1 could AND channel map 402 and 404, similar to above, and thenaverage the QOS values for channels appearing in both of channel maps402 and 404. Access point 150-1 could then select only the channels thatappear in both of channel maps 402 and 404 that have an average QOSvalue that exceeds a threshold value. The resulting channels could thenbe incorporated into channel map 406. In this example, instead ofaveraging corresponding QOS values for corresponding channels, accesspoint 150-1 could also select the minimum QOS value for eachcorresponding channel. Access point 150-1 could then compare the minimumQOS values to the threshold to identify channels that should beincorporated into channel map 406.

Access point 150-1 may also implement a wide variety of filteringtechniques in order to combine channel maps 402 and 404. For example,access point 150-1 could implement a Kalman filter in order to smoothchannel maps 402 and 404 into a single channel map 406. Persons skilledin the art will recognize that access point 150-1 may implement anytechnically feasible approach for generating a single set of data basedon two different sets of data in order to generate channel map 406 basedon channels maps 402 and 404. Upon combining channel maps 402 and 404using any of the aforementioned techniques, access point 150-1 transmitschannel map 406 to node 130. Node 130 may then transmit channel map 406to adjacent nodes 130. Access point 150-1 or node 130 may also transmitchannel map 406 to other access points 150, thereby precluding the needfor further combination of channel maps for a period of time.

Each of access points 150-1 and 150-2 may also implement the techniquesdescribed thus far upon exchanging channel maps 402 and 404 with oneanother, as described in greater detail below in conjunction with FIG.4B.

FIG. 4B illustrates a portion 410 of the network system 100 of FIG. 1configured to combine channel maps 402 and 404 associated with accesspoints 150-1 and 150-2, respectively, according to one embodiment of thepresent invention. As shown, access point 150-1 includes channel map 402and access point 150-2 includes channel map 404. Access points 150-1 and150-2 are configured to exchange channel maps 402 and 404 with oneanother, as also shown.

Upon receiving channel map 404 from access point 150-2, access point150-1 may combine channel map 402 with channel map 404 to generatechannel map 406. Access point 150-1 may implement any of the techniquesdescribed in conjunction with FIG. 4A for combining channel maps. Inlike fashion, upon receiving channel map 402 from access point 150-1,access point 150-2 may combine channel map 404 with channel map 402 togenerate channel map 406. Access point 150-2 generally implements thesame combination technique as access point 150-2, and so channel map 406generate by access point 150-2 is substantially similar to channel map406 generated by access point 150-1.

Access points 150-1 and 150-2 are configured to transmit channel maps406 to node 130. Although node 130 receives multiple channel maps frommultiple access points 150, those channel maps are essentially the same,and so node 130 is not presented with conflicting information. Node 130may then communicate with other nodes 130 according to the channelsincluded within channel map 406 and may also transmit channel map 406 tothose other nodes 130 or access points 150. Access points 150-1 and150-2 may also transmit channel map 406 to other access points 150 andto other nodes 130, thereby providing those access points and nodes witha channel map that is consistent across those different devices.

Node 130 may also implement the techniques described thus far uponreceiving channel maps 402 and 404 from access points 150-1 and 150-2,respectively, as described in greater detail below in conjunction withFIG. 4C.

FIG. 4C illustrates a portion 420 of the network system 100 of FIG. 1configured to combine channel maps 402 and 404 associated with accesspoints 150-1 and 150-2, respectively, according to one embodiment of thepresent invention. As shown, access point 150-1 includes channel map 402and access point 150-2 includes channel map 404. Access points 150-1 and150-2 are configured to transmit channel maps 402 and 404, respectively,to node 130. Node 130 is configured to combine channel maps 402 and 404by implementing any of the aforementioned techniques for combiningchannel maps. Node 130 may then transmit channel map 406 to adjacentnodes and/or access points 150 to which node 130 is coupled.

In one embodiment, access points 150-1 and 150-2 may transmit to node130 just the channels within channel maps 402 and 404, respectively,with a QOS value that exceeds a threshold value. With this approach,access points 150 may transmit a reduced amount of information to node130. Node 130 may then combine these different portions of channels maps402 and 404 to generate channel map 406.

Referring generally to FIGS. 1 and 4A-4C, any technically feasibledevice included in the network system 100 may implement the combinationtechniques described thus far. For example, server 154 may be configuredto combine an older version of a particular channel map with a newerversion of that channel map and then provide the combined channel map toaccess points 150. As a general matter, the combination of channel mapsrepresents an operation that may be carried out by any device within thenetwork system of FIG. 1 according to the computational resourcesassociated with those devices.

For example, in network systems such as portion 400 shown in FIG. 1,nodes 130 and access point 150-2 could lack sufficient computationalresources to combine channel maps 402 and 404 compared to thecomputational resources available to access point 150-1. Therefore,access point 150-1 would assume responsibility for combining channelmaps 402 and 404. Alternatively, in network systems such as portion 420,nodes 130 may be equipped with sufficient computational resources tocombine channel maps, and so each node 130 may assume responsibility forcombining any and all received channel maps.

In addition, different devices included in the network system 100 mayimplement different portions of the techniques described thus far. Forexample, an access point 150-1 could perform an AND operation with twochannel maps to generate a third channel map, as described inconjunction with FIG. 4A. Then, a node 130 could select channels fromwithin the third channel map based on QOS values associated with thosechannels. Persons skilled in the art will recognize that the techniquesdescribed in conjunction with FIGS. 4A-4C may be combined and/ordistributed in any technically feasible fashion.

In some situations, a node 130 may be included within a mobile device,such as a cellular phone or tablet computer. Accordingly, the node 130may travel through many different regions with widely varying channelavailability and channel QOS values. In order to provide the node 130with a channel map that is relevant within those different regions,access points 150 and/or nodes 130 may implement the techniquesdescribed below in conjunction with FIG. 5.

Each of FIGS. 5A-5B illustrates a portion of the network system of FIG.1 that is configured to generate a channel map based on the predictedposition of a node, according to various embodiments of the presentinvention. FIGS. 5A-5B include some of the same components as thoseshown in FIGS. 1 and 4A-4C, although certain components have beenomitted, for the sake of simplicity, while other components have beenadded.

FIG. 5A illustrates a portion 500 of the network system of FIG. 1 thatis configured to generate a channel map 530 based on the predictedposition of node 130, according to one embodiment of the presentinvention. As shown, node 130 resides at a position 502 within a region504. Region 504 may represent any arbitrary space, such as ageographical region, a region within which certain laws apply, a regionassociated with a protected user, and so forth. In one embodiment,region 504 is defined by a boundary within which a TV tower 506 isauthorized to operate on a first TV channel with a given power level. InFIG. 5, node 130 resides within region 504 at a time t0. However, thelocation of node 130 is not fixed, and node 130 may traverse from region504 along path 508 to another region 514. Within region 514, node 130may reside at a position 512 at a future time t1.

Access point 150 is configured to analyze the movements of node 130 andto predict the future position of node 130 at various future times. Inparticular, access point 150 is configured to predict that, at time t1,node 130 will reside at position 512 within region 514. Access point 150may implement any technically feasible approach for predicting themovements of node 130. For example, access point 150 could record theposition of node 130 at various times and estimate the velocity of node130 in a certain direction, and then extrapolate the position of node130 based on the estimated velocity of node 130. Persons skilled in theart will recognize that may other techniques for predicting the positionof a moving object are known in the art, and that access point 150 mayimplement any of those existing techniques.

Access point 150 is also configured provide a channel map 530 to node130 that is associated with both regions 504 and 514 and indicateschannels that are available within both of those regions. Channel map530 may also indicate QOS values for the various channels in channel map530. Node 130 may then rely on channel map 530 while residing withineither region 504 or region 514. Consequently, node 130 may not need toacquire a new channel map upon leaving region 504 and entering region514. Additionally, if node 130 selects a channel on which to communicatefrom channel map 530, then node 130 may not need to change channels whentraversing between regions 504 and 514, because any selected channelshould be available within both of those regions.

Access point 150 is configured to generate channel map 530 by firstacquiring channel map 522 that is associated with region 504 and validat time t0. Upon predicting that node 130 will reside within region 514at time t1, access point 150 may then acquire a channel map 524 that isassociated with region 514 and valid at time t1. Access point 150 maythen combine channel map 522 with channel map 524 to generate channelmap 530. Access point 150 could, for example, perform an AND operationwith channel maps 522 and 524 to identify channels that are includedwithin both such channel maps. Access point 150 could also identifychannels to include within channel map 530 based on the QOS values ofchannels that appear in both of channel maps 522 and 524. Generally,access point 150 may combine channels maps 522 and 524 by implementingany of the combination techniques described above in conjunction withFIGS. 4A-4C.

Node 130 is also configured to implement the combination techniquedescribed above, as described in greater detail below in conjunctionwith FIG. 5B.

FIG. 5B illustrates a portion 540 of the network system of FIG. 1 thatis configured to generate a channel map 530 based on the predictedposition of node 130, according to one embodiment of the presentinvention. As shown, access point 150 is configured to transmit channelmaps 522 and 524 to node 130. Node 130 may then combine channel maps 522and 524 to generate channel map 530. Node 130 may implement any of thechannel map combination techniques described thus far in order togenerate channel map 530.

Referring generally to FIGS. 5A and 5B, access point 150, node 130, orany other device within the network system 100 may combine channel mapsassociated with any number of different regions that node 130 mayoccupy. For example, access point 150 could predict that node 130 willtraverse three separate regions during three different time intervals,and then acquire channel maps associated with those three regions.Access point 150 could then combine those three channel maps and providethe combined channel map to node 130.

The techniques described above in conjunction with FIGS. 4A-4C and 5A-5Bmay also be implemented in concert with one another, as described ingreater detail below in conjunction with FIG. 6A-6C.

Each of FIGS. 6A-6C illustrates a portion of the network system 100 ofFIG. 1 configured to combine different channel maps associated withvarious positions of a node, according to various embodiments of thepresent invention. FIGS. 6A-6C include some of the same components asthose shown in FIGS. 1, 4A-4C, and 5A-5B, although certain componentshave been omitted, for the sake of simplicity, while other componentshave been added.

FIG. 6A illustrates a portion 600 of the network system 100 of FIG. 1configured to combine different channel maps associated with variouspositions of node 130, according to one embodiment of the presentinvention. As shown, portion 600 includes access points 150-1 and 150-2.Node 130 is coupled to both access point 150-1 and access point 150-2.Access point 150-1 includes channel maps 622 and 624. Access point 150-2includes channel maps 626 and 628.

Channel map 622 within access point 150-1, and channel map 626 withinaccess point 150-2, both include lists of channels associated withregion 504. Those channel maps may also include QOS values and/or othermetrics that characterize channels associated with region 504. However,channel maps 622 and 626 are different from one another and thereforeinclude different lists of channels. Channel maps 622 and 626 may differfrom one another, for example, because one of those channel maps wasgenerated at a different time than the other channel map. Access points150-1 and 150-2 may acquire channels maps 622 and 626, respectively,upon determining that node 130 resides within region 504 at a currenttime t0.

Similarly, channel map 624 within access point 150-1, and channel map628 within access point 150-2, both include lists of channels associatedwith region 514. Those channel maps may also include QOS values and/orother metrics that characterize channels associated with region 514.However, like channel maps 622 and 626, channel maps 624 and 628 aredifferent from one another and therefore include different lists ofchannels. Access points 150-1 and 150-2 may acquire channels maps 624and 628, respectively, upon predicting that node 130 may reside withinregion 514 at a future time t1.

Access points 150-1 and 150-2 are configured to operate in conjunctionwith one another to resolve any differences between those differentchannel maps. Access points 150-1 and 150-2 may combine differentchannel maps associated with the same region, and may also combinedifferent channel maps associated with different regions. In doing so,access point 150-2 is configured to transmit channel maps 626 and 628 toaccess point 150-1. Access point 150-1 may then combine channel maps622, 624, 626, and 628 the generate channel map 630.

Access point 150-1 may implement any of the channel map combinationtechniques described thus far, in any order and with any pair of channelmaps to generate combined channel maps. For example, access point 150-1could combine channel maps 622 and 626 to generate a first combinedchannel map, and then combine channel maps 624 and 628 to generate asecond combined channel map. Access point 150-1 could then combine thefirst combined channel map with the second combined channel map togenerate channel map 630. Persons skilled in the art will recognize thatany approach to combining channel maps 622, 624, 626, and 628 fallswithin the scope of the present invention.

With the approach described herein, access points 150-1 and 150-2 areconfigured to provide node 130 with a channel map that is (i) consistentbetween access points 150-1 and 150-2 and (ii) incorporates channelsthat are available in both of the regions 504 and 514.

Each of access points 150-1 and 150-2 may also implement the techniquesdescribed thus far upon exchanging channel maps with one another, asdescribed in greater detail below in conjunction with FIG. 6B.

FIG. 6B illustrates a portion 640 of the network system 100 of FIG. 1configured to combine different channel maps associated with variouspositions of a node 130, according to one embodiment of the presentinvention. As shown, access point 150-1 is configured to transmitchannel maps 622 and 624 to access point 150-2, and access point 150-2is configured to transmit channel maps 626 and 628 to access point150-1.

Access point 150-1 may then combine channel maps 622, 624, 626 and 628to generate channel map 630. Access point 150-1 then transmits channelmap 630 to node 130. By implementing a similar approach, access point150-2 is configured to combine channel maps 622, 624, 626 and 628 togenerate channel map 630. Access points 150-2 then transmits channel map630 to node 130. Since access points 150-1 and 150-2 implement a similarapproach to combining channel maps, those access points 150 mayindependently generate essentially the same channel map 630.

Node 130 may also implement the techniques described thus far uponreceiving channel maps 622 and 624 from access point 150-1 and channelmaps 626 and 628 from access point 150-2, as described in greater detailbelow in conjunction with FIG. 6C.

FIG. 6C illustrates a portion 680 of the network system 100 of FIG. 1configured to combine different channel maps associated with variouspositions of a node 130, according to one embodiment of the presentinvention. As shown, access point 150-1 is configured to transmitchannel maps 622 and 624 to node 130, and access point 150-2 isconfigured to transmit channel maps 626 and 628 to node 130. Node 130 isconfigured to combine those different channel maps to generate channelmap 630. Node 130 may then transmit channel map 630 to adjacent nodesand/or access points 150 to which node 130 is coupled.

Persons skilled in the art will recognize that any of the approachesdescribed thus far may be implemented in conjunction with one another.For example, access points 150-1 and 150-2 may be configured to combinechannel maps 622 and 626 with one another and provide a combined channelmap to node 130. Node 130 may then acquire channel maps 624 and 628(e.g. from server 154 or from another source) and then merge thosechannel maps with the combined channel map received from access points150-1 and 150-2. Any and all such combinations fall within the scope ofthe present invention. Persons skilled in the art will also recognizethat the techniques described herein may be implemented to combine anynumber of different channel maps. In addition, as previously mentioned,any technically feasible approach for combining channel maps also fallswithin the scope of the invention, and any such approach may beimplemented by any device included within the network system 100.

In addition, persons skilled in the art will recognize that theapproaches described thus far may be implemented with any type of whitespace network, and, more generally, with any technically feasible classof network. For example, nodes 130, access points 150, server 154, andother devices described herein may reside within a star network orpersonal area network (PAN) and implement the different approachesdescribed herein. Further, those devices may reside within a networkhaving a tiered priority system (a tiered network) and generate, orotherwise acquire, channel maps that account for the priorities of otherdevices within the network. In a tiered network, high-priority devicesmay have a higher transmit power, or more relaxed out-of-band transmitrules compared to nodes 130. The priorities of the different devices inthe network may be derived from specific licensing agreements thatregulate the operation of those devices. A tiered network could be, forexample, a network compliant with the T108 network in Japan. In thecontext of a T108 network, a node could generate, or otherwise acquire,a channel map that accounts for the priorities of other devices in thatT108 network.

The various techniques described above in conjunction with FIGS. 1-6Care also described in greater detail below in conjunction with FIGS.7-9.

FIG. 7 is a flow diagram of method steps for combining different channelmaps, according to one embodiment of the present invention. Although themethod steps are described in conjunction with the systems of FIGS.1-6C, persons skilled in the art will understand that any systemconfigured to perform the method steps, in any order, is within thescope of the present invention.

As shown, a method 700 begins at step 702, where access point 150-1determines the location of node 130. Node 130 could, for example, reportthat location to access point 150, or access point 150 could track themovements of node 130, among other possibilities. At step 704, accesspoint 150-1 acquires channel map 402 that corresponds to the location ofnode 130. Channel map 402 includes a list of channels that are availableat the location of node 130 and may also include QOS values for thosechannels. Access point 150-1 may acquire channel map 402 from publicdatabase 158, private database 160, server 154, or any other location.

At step 706, access point 150-1 acquires channel map 404 thatcorresponds to the location of node 130 and is associated with accesspoint 150-2. Access point 150-1 may acquire channel map 404 directlyfrom access point 150-2, as shown in FIG. 4A. Channel maps 402 and 404are both associated with the location of node 130, however, thosechannel maps may differ from one another for a variety of reasons. Forexample, channel map 402 could have been generated after channel map404, and could thus represent a more current list of channels associatedwith the position of node 130.

At step 708, access point 150-1 combines channel map 402 with channelmap 404 to generate channel map 406. Access point 150-1 may implementany technically feasible approach for combining different sets of data,including performing an AND operation with channel maps 402 and 404,among other possible techniques. At step 710, access point 150-1 causesnode 130 to operation according to channel map 406. For example, accesspoint 150-1 could transmit channel map 406 to node 130, as shown in FIG.4A. The method 700 then ends.

By implementing the method 700, access point 150-1 may combine differentchannel maps associated with location of node 130, thereby reconcilingconflicting information that may be present within those differentchannel maps. Although the method 700 has been described as beingperformed by access point 150-1, as shown in FIG. 4A, the method 700 mayalso be performed by both access points 150-1 and 150-2, as describedabove in conjunction with FIG. 4B, or by node 130 itself, as describedabove in conjunction with FIG. 4C.

FIG. 8 is a flow diagram of method steps for generating a channel mapfor the predicted position of a node, according to one embodiment of thepresent invention. Although the method steps are described inconjunction with the systems of FIGS. 1-6C, persons skilled in the artwill understand that any system configured to perform the method steps,in any order, is within the scope of the present invention.

As shown, a method 800 begins at step 802, where access point 150determines the location of node 130 at time t0. At time t0, node 130resides within region 504, as shown in FIG. 5A. At step 804, accesspoint 150 determines the predicted location of node 130 at time t1. Attime t1, node 130 may reside within region 514, as also shown in FIG.5A. Access point 150 may predict the future location of node 130 byaggregating position information associated with node 130 and thenextrapolating that position information. For example, access point 150could determine the velocity of node 130 in a certain direction, andthen determine the distance that will be traveled by node 130 in thatdirection over a time interval given by t1 minus t0.

At step 806, access point 150 acquires channel map 522 that correspondsto region 504 and is valid at time t0. Access point 150 may retrievechannel map 522 from public database 158 or private database 160, oracquire channel map 522 by interacting with server 154, among otherpossibilities. At step 808, access point 150 acquires channel map 522that corresponds to region 514 and is valid at time t1. Similarly,access point 150 may retrieve channel map 524 from public database 158or private database 160, acquire channel map 524 by interacting withserver 154, and so forth.

At step 810, access point 150 combines channel map 522 with channel map524 to generate channel map 530. Channel map 530 is associated with bothregions 504 and 514 and indicates channels that are available withinboth of those regions. Channel map 530 may also indicate a collection ofQOS values. Access point 150 may combine channel maps 522 and 524 byimplementing any of the channel map combination techniques describedthus far.

At step 812, access point 150 causes node 130 to operate according tochannel map 530. The method 800 then ends. Node 130 may then rely onchannel map 530 while residing within either region 504 or region 514.Consequently, node 130 may not need to acquire a new channel map uponleaving region 504 and entering region 514. Additionally, if node 130selects a channel on which to communicate from channel map 530, thennode 130 may not need to change channels when traversing between regions504 and 514, because any selected channel should be available withinboth of those regions.

By implementing the method 800, access point 150 may combine channelmaps associated with the current location of node 130 as well as thepredicted location of node 130 at a future time, thereby reducing thenumber of channel maps that must be transmitted to node 130. Althoughthe method 800 has been described as being performed by access point150, as shown in FIG. 5A, the method 800 may also be performed by node130, as described above in conjunction with FIG. 5B.

FIG. 9 is a flow diagram of method steps for combining different channelmaps associated with the predicted position of a node, according to oneembodiment of the present invention. Although the method steps aredescribed in conjunction with the systems of FIGS. 1-6C, persons skilledin the art will understand that any system configured to perform themethod steps, in any order, is within the scope of the presentinvention.

As shown, a method 900 begins at step 902, where access point 150-1determines the location of node 130 at time t1. At time t1, node 130resides within region 504, as shown in FIG. 6A. Access point 150-2 mayalso determine the location of node 130 at time t0 by performing step902. At step 904, access point 150-1 determines the predicted locationof node 130 at time t1. At time t1, node 130 may reside within region514, as shown in FIG. 6A. Access point 150-2 may also determine thepredicted location of node 130 at time t1 by performing step 904.

At step 906, access point 150-1 acquires channel map 622 thatcorresponds to region 504 and is valid at time t0. At step 908, accesspoint 150-1 acquires channel map 624 that corresponds to region 514 andis valid at time t1. Access point 150-1 may query public database 158 orprivate database 160 for channel maps 622 and 624, or may communicatewith server 154 in order to cause server 154 to retrieve those maps fromthose different databases.

At step 910, access point 150-1 acquires channel map 626 from accesspoint 150-2. Channel map 626 corresponds to region 504 and is valid attime t0, yet is different from channel map 622, which also correspondsto region 504 and similarly valid. Channel maps 622 and 626 could havebeen generated at different times, or could be different for a varietyof other reasons. At step 912, access point 150-1 acquires channel map628 from access point 150-2. Channel map 628 corresponds to region 514and is valid at time t1, yet is different from channel map 624, whichalso corresponds to region 514 and is similarly valid. Similar tochannel maps 622 and 626, channel maps 624 and 628 could have beengenerated at different times, or could be different for a variety ofother reasons.

At step 914, access point 150-1 combines channel maps 622, 624, 626, and628 to generate channel map 630. Access point 150-1 may implement anychannel map combination technique described herein. At step 916, accesspoint 150-1 causes node 130 to operate according to channel map 630. Themethod 900 then ends. Channel map 630 is consistent between accesspoints 150-1 and 150-2 and also incorporates channels that are availablein both of the regions 504 and 514.

By implementing the method 900, access point 150-1 may resolvediscrepancies between different channel maps that both correspond to thesame region, and may also combine channel maps corresponding todifferent regions, thereby combining the techniques associated with themethods 700 and 800, described above on conjunction with FIGS. 7 and 8,respectively.

In sum, an access point coupled to a node within a network is configuredto combine channel maps provided by other access points to which thenode is coupled, thereby reconciling any discrepancies between thosechannel maps. The access point may also combine channel maps associatedwith different regions that the node may occupy, thereby reducing thenumber of channel maps that must be transmitted to the node when thenode travel between regions.

Advantageously, the node is provided with a single channel map that isconsistent across all access points to which the node is coupled andrelevant within multiple regions that the node may occupy. Thus, thedisclosed techniques may reduce the number of channel maps that must betransmitted to the node, thereby decreasing overall network traffic. Inaddition, the node does not need to change communication channels whencoupled to different access points or when traversing between differentregions. Accordingly, downtime associated with changing communicationchannels may be eliminated, thus improving the efficiency with which thenode operates.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof. For example, aspects of thepresent invention may be implemented in hardware or software or in acombination of hardware and software. One embodiment of the inventionmay be implemented as a program product for use with a computer system.The program(s) of the program product define functions of theembodiments (including the methods described herein) and can becontained on a variety of computer-readable storage media. Illustrativecomputer-readable storage media include, but are not limited to: (i)non-writable storage media (e.g., read-only memory devices within acomputer such as CD-ROM disks readable by a CD-ROM drive, flash memory,ROM chips or any type of solid-state non-volatile semiconductor memory)on which information is permanently stored; and (ii) writable storagemedia (e.g., floppy disks within a diskette drive or hard-disk drive orany type of solid-state random-access semiconductor memory) on whichalterable information is stored. Such computer-readable storage media,when carrying computer-readable instructions that direct the functionsof the present invention, are embodiments of the present invention.

In view of the foregoing, the scope of the present invention isdetermined by the claims that follow.

The invention claimed is:
 1. A computer-implemented method forgenerating a channel map for a first node within a network, the methodcomprising: acquiring a first channel map that includes a first set ofchannels on which the first node is configured to communicate, whereinthe first channel map is generated by a first access point based on afirst physical region in which the first node resides; acquiring asecond channel map that includes a second set of channels on which thefirst node is configured to communicate, wherein the second channel mapis generated by a second access point based on either the first physicalregion or a second physical region in which the first node is predictedto reside, wherein the first physical region is different than thesecond physical region, and wherein the second access point transmitsthe second channel map to either the first access point or the firstnode; combining the first channel map with the second channel map togenerate a third channel map that resolves one or more conflicts betweenthe first channel map and the second channel map, wherein a firstchannel included in the first channel map is added to the third channelmap when performing an operation on both a quality of service value forthe first channel and a quality of service value for a correspondingchannel included in the second channel map generates a result that meetsa first criterion; and causing the first node to communicate on achannel included in the third channel map, wherein each of the firstchannel map, the second channel map, and the third channel map specifiesone or more channels within a television white space that are availableto the first node for communications.
 2. The computer-implemented methodof claim 1, wherein the first channel map is stored in the first accesspoint that serves the first physical region in which the first noderesides, and the second channel map is acquired from the second accesspoint that serves the second physical region in which the first node ispredicted to reside, and further comprising transmitting the thirdchannel map from the first access point to the node.
 3. Thecomputer-implemented method of claim 1, wherein the first channel mapcomprises a combination of a channel map stored by the first accesspoint to which the first node is coupled and a channel map stored by thesecond access point to which the first node is coupled.
 4. Thecomputer-implemented method of claim 3, wherein the second channel mapcomprises a combination of a channel map associated with the firstphysical region in which the first node resides and a channel mapassociated with the second physical region in which the first node ispredicted to reside.
 5. The computer-implemented method of claim 1,wherein combining the first channel map with the second channel mapcomprises performing an AND operation between the first set of channelsand the second set of channels, and the operation performed on both thequality of service value for the first channel and the quality ofservice value for the corresponding channel comprises one or moremathematical operations.
 6. The computer-implemented method of claim 1,wherein the first channel map includes a quality of service value forthe first set of channels, and the second channel map includes a qualityof service value for the second set of channels.
 7. Thecomputer-implemented method of claim 1, wherein the operation comprisescomputing an average between the quality of service value for the firstchannel included in the first channel map and the quality of servicevalue for the corresponding channel included in the second channel map,and the first channel is added to the third channel map when the averageexceeds a threshold value.
 8. The computer-implemented method of claim1, wherein the operation comprises computing a minimum value of thequality of service value for the first channel included in the firstchannel map and the quality of service value for the correspondingchannel included in the second channel map, and the first channel isadded to the third channel map when the minimum value exceeds athreshold value.
 9. The computer-implemented method of claim 1, furthercomprising transmitting the third channel map from the first accesspoint to the first node.
 10. The computer-implemented method of claim 9,further comprising: acquiring, at the second access point, the firstchannel map; acquiring, at the second access point, the second channelmap; combining, at the second access point, the first channel map withthe second channel map to generate a second version of the third channelmap; and transmitting the second version of the third channel map fromthe second access point to the first node.
 11. The computer-implementedmethod of claim 1, wherein the first access point acquires the secondchannel map from the second access point that is also coupled to thefirst node.
 12. The computer-implemented method of claim 1, furthercomprising: acquiring, at the first access point, a fourth channel map;acquiring, at the first access point, a fifth channel map; transmittingthe first channel map to the second access point; combining, at thefirst access point, the first channel map, the second channel map, thefourth channel map, and the fifth channel map to generate a firstversion of a sixth channel map; and transmitting the first version ofthe sixth channel map from the first access point to the first node. 13.The computer-implemented method of claim 12, further comprising:acquiring, at the second access point, the first channel map from thefirst access point; transmitting the fourth channel map and the fifthchannel map to the first access point; combining, at the second accesspoint, the first channel map, the second channel map, the fourth channelmap, and the fifth channel map to generate a second version of the sixthchannel map; and transmitting the second version of the sixth channelmap from the second access point to the first node, wherein the firstnode is configured to communicate on a channel included in the firstversion of the sixth channel map or the second version of the sixthchannel map.
 14. One or more non-transitory computer-readable mediathat, when executed by one or more processors, cause the one or moreprocessors to generate a channel map for a first node within a networkby performing the steps of: acquiring a first channel map that includesa first set of channels on which the first node is configured tocommunicate, wherein the first channel map is generated by a firstaccess point based on a first physical region in which the first noderesides; acquiring a second channel map that includes a second set ofchannels on which the first node is configured to communicate, whereinthe second channel map is generated by a second access point based oneither the first physical region or a second physical region in whichthe first node is predicted to reside, wherein the first physical regionis different than the second physical region, and wherein the secondaccess point transmits the second channel map to either the first accesspoint or the first node; combining the first channel map with the secondchannel map to generate a third channel map that resolves one or moreconflicts between the first channel map and the second channel map,wherein a first channel included in the first channel map is added tothe third channel map when performing an operation on both a quality ofservice value for the first channel and a quality of service value for acorresponding channel included in the second channel map generates aresult that meets a first criterion; and causing the first node tocommunicate on a channel included in the third channel map, wherein eachof the first channel map, the second channel map, and the third channelmap specifies one or more channels within a television white space thatare available to the first node for communications.
 15. The one or morenon-transitory computer-readable media of claim 14, wherein the firstchannel map is stored in the first access point that serves the firstphysical region in which the first node resides, and the second channelmap is acquired by the first access point from the second access pointthat serves the second physical region in which the first node ispredicted to reside, and further comprising transmitting the thirdchannel map from the first access point to the node.
 16. The one or morenon-transitory computer-readable media of claim 14, wherein the firstchannel map comprises a combination of a channel map stored by the firstaccess point to which the first node is coupled and a channel map storedby the second access point to which the first node is coupled.
 17. Theone or more non-transitory computer-readable media of claim 16, whereinthe second channel map comprises a combination of a channel mapassociated with the first physical region in which the first noderesides and a channel map associated with the second physical region inwhich the first node is predicted to reside.
 18. The one or morenon-transitory computer-readable media of claim 14, wherein the step ofcombining the first channel map with the second channel map comprisesperforming an AND operation between the first set of channels and thesecond set of channels, and the operation performed on both the qualityof service value for the first channel and the quality of service valuefor the corresponding channel comprises one or more mathematicaloperations.
 19. The one or more non-transitory computer-readable mediaof claim 14, wherein the first channel map includes a quality of servicevalue for the first set of channels, and the second channel map includesa quality of service value for the second set of channels.
 20. The oneor more non-transitory computer-readable media of claim 14, wherein theoperation comprises computing an average between the quality of servicevalue for the first channel included in the first channel map and thequality of service value for the corresponding channel included in thesecond channel map, and the first channel is added to the third channelmap when the average exceeds a threshold value.
 21. The one or morenon-transitory computer-readable media of claim 14, wherein theoperation comprises computing a minimum value of the quality of servicevalue for the first channel included in the first channel map and thequality of service value for the corresponding channel included in thesecond channel map, and the first channel is added to the third channelmap when the minimum value exceeds a threshold value.
 22. Thenon-transitory computer-readable medium of claim 14, wherein theoperation performed on both the quality of service value for the firstchannel and the quality of service value for the corresponding channelcomprises one or more mathematical operations.
 23. The non-transitorycomputer-readable medium of claim 14, wherein the operation performed onboth the quality of service value for the first channel and the qualityof service value for the corresponding channel comprises computing atleast one of: an average between the quality of service value for thefirst channel and the quality of service value for the correspondingchannel, and a minimum value of the quality of service value for thefirst channel and the quality of service value for the correspondingchannel, and wherein the first channel is added to the third channel mapat least one of when the average exceeds a first threshold value andwhen the minimum value exceeds a second threshold value.
 24. A systemfor generating a channel map for a first node within a network,including: one or more processors configured to: acquire a first channelmap that includes a first set of channels on which the first node isconfigured to communicate, wherein the first channel map is generated bya first access point based on a first physical region in which the firstnode resides; acquire a second channel map that includes a second set ofchannels on which the first node is configured to communicate, whereinthe second channel map is generated by a second access point based oneither the first physical region or a second physical region in whichthe first node is predicted to reside, wherein the first physical regionis different than the second physical region, and wherein the secondaccess point transmits the second channel map to either the first accesspoint or the first node; combine the first channel map with the secondchannel map to generate a third channel map that resolves one or moreconflicts between the first channel map and the second channel map,wherein a first channel included in the first channel map is added tothe third channel map when performing an operation on both a quality ofservice value for the first channel and a quality of service value for acorresponding channel included in the second channel map generates aresult that meets a first criterion; and cause the first node tocommunicate on a channel included in the third channel map, wherein eachof the first channel map, the second channel map, and the third channelmap specifies one or more channels within a television white space thatare available to the first node for communications.
 25. The system ofclaim 24, further including: one or more memories coupled to the one ormore processors and storing program instructions that, when executed bythe one or more processors, cause the one or more processors to: acquirethe first channel map; acquire the second channel map; combine the firstchannel map with the second channel map; and cause the first node tocommunicate on the channel included in the third channel map.
 26. Acomputer-implemented method for generating a channel map for a firstnode within a network, the method comprising: acquiring a first channelmap that includes a first set of channels on which the first node isconfigured to communicate, wherein the first channel map is generatedbased on a first physical region in which the first node resides,wherein the first channel map is stored in a first access point thatserves the first physical region; acquiring, by the first access pointfrom a second access point that serves a second physical region in whichthe first node is predicted to reside, a second channel map thatincludes a second set of channels on which the first node is configuredto communicate, wherein the second channel map is generated based oneither the first physical region or the second physical region, whereinthe first physical region is different than the second physical region,and wherein the first access point determines the second physical regionin which the first node is predicted to reside; combining, by the firstaccess point, the first channel map with the second channel map togenerate a third channel map that resolves one or more conflicts betweenthe first channel map and the second channel map, wherein a firstchannel included in the first channel map is added to the third channelmap when performing an operation on both a quality of service value forthe first channel and a quality of service value for a correspondingchannel included in the second channel map generates a result that meetsa first criterion, and channels associated with one or more quality ofservice values below a threshold value are not added to the thirdchannel map; and causing the first node to communicate on a channelincluded in the third channel map, wherein each of the first channelmap, the second channel map, and the third channel map specifies one ormore channels within a television white space that are available to thefirst node for communications.
 27. One or more non-transitorycomputer-readable media that, when executed by one or more processors,causes the one or more processors to generate a channel map for a firstnode within a network by performing the steps of: acquiring a firstchannel map that includes a first set of channels on which the firstnode is configured to communicate, wherein the first channel map isgenerated based on a first physical region in which the first noderesides, wherein the first channel map is stored in a first access pointthat serves the first physical region; acquiring, by the first accesspoint from a second access point that serves a second physical region inwhich the first node is predicted to reside, a second channel map thatincludes a second set of channels on which the first node is configuredto communicate, wherein the second channel map is generated based oneither the first physical region or the second physical region, whereinthe first physical region is different than the second physical region,and wherein the first access point determines the second physical regionin which the first node is predicted to reside; combining, by the firstaccess point, the first channel map with the second channel map togenerate a third channel map that resolves one or more conflicts betweenthe first channel map and the second channel map, wherein a firstchannel included in the first channel map is added to the third channelmap when performing an operation on both a quality of service value forthe first channel and a quality of service value for a correspondingchannel included in the second channel map generates a result that meetsa first criterion, and channels associated with one or more quality ofservice values below a threshold value are not added to the thirdchannel map; and causing the first node to communicate on a channelincluded in the third channel map, wherein each of the first channelmap, the second channel map, and the third channel map specifies one ormore channels within a television white space that are available to thefirst node for communications.